Manifold Drain Plug Kit – Fits Volvo Penta GM V6 V8 4.3 5.0 5.7 7.4 8.2 (Replaces 479956, GLM13982, 192154)

Product Details

This Manifold Drain Plug Kit is engineered for Volvo Penta GM-based V6 and V8 marine engines, including 4.3L, 5.0L, 5.7L, 7.4L, and 8.2L models. The kit features quick-drain plastic cocks located on the rear (propeller side) of the exhaust manifold for efficient winterization and maintenance.

Direct aftermarket replacement for OEM part numbers 479956, GLM13982, and 192154, ensuring compatibility with Volvo Penta and select OMC applications.

• Quick-drain design with plastic handle for tool-free operation
• Metric thread specifications: 20.50mm × 1.75 outer, 2.5mm × 10.70mm handle diameter
• Complete kit includes two drain plugs for dual-manifold installations

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Engine & Model Compatibility

Confirm your engine model/year in the table below.

Technical Specs

Outer Thread

20.50mm × 1.75 metric

Handle Thread

2.5 metric

Handle Diameter

10.70mm

Valve Type

Quick-drain plastic cock

Material

Marine-grade plastic with brass insert

Installation Location

Rear side of exhaust manifold (propeller side)

What's in the Box

• 2 × Exhaust Manifold Drain Plug Kit

Installation Notes

1. Ensure engine is cool and depressurized before beginning work.
2. Locate the existing drain plugs on the rear (propeller side) of each exhaust manifold.
3. Remove old drain plugs by unscrewing counterclockwise; have a container ready to catch residual coolant.
4. Clean the threads in the manifold port thoroughly to remove debris or corrosion.
5. Hand-thread the new drain plug clockwise until snug; avoid cross-threading.
6. Tighten securely but do not over-torque the plastic components.
7. Ensure the drain cock is in the closed position before refilling the cooling system.
8. Refill coolant to manufacturer specifications and bleed air from the system.
9. Start the engine and check for leaks around both drain plugs.
10. For winterization, open both cocks fully to drain coolant completely.

Troubleshooting & FAQ

Will this fit my Volvo Penta engine?

This kit is designed for GM-based V6 and V8 Volvo Penta engines (4.3L, 5.0L, 5.7L, 7.4L, 8.2L). It also fits select OMC 4.3L and 5.7L GM-based models. Verify your existing drain plug has 20.50mm × 1.75 metric threads before ordering.

How do I use the quick-drain feature?

Rotate the plastic handle 90 degrees to open the valve and drain coolant. Close it completely before refilling. The tool-free design simplifies winterization and seasonal maintenance.

Can I reuse the old drain plugs?

Drain plugs should be replaced if cracked, stripped, or leaking. Plastic components degrade over time from heat cycling and coolant exposure, so replacement every few seasons is recommended.

What's the difference between this and the OEM part?

This is an aftermarket replacement built to OEM specifications with comparable materials and thread dimensions. Manufactured in an ISO 9002 facility and batch-inspected for dimensional accuracy and valve operation.

Why do I need two drain plugs?

V6 and V8 engines have two exhaust manifolds, each requiring its own drain plug for complete coolant drainage during winterization or service.

How often should I replace these plugs?

Inspect annually for cracks, hard plastic, or difficult operation. Replace every 3–5 years or immediately if leaking or stripped.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

• Verify images/specifications against your original part. If anything differs—even if your model appears compatible—do not purchase.
• This is an aftermarket replacement, not an OEM component.
• Professional installation is recommended for safety and performance.

About Sea Sierra

• Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
• Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
• Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.